Thin film transistor array panel and display device

ABSTRACT

A display device includes a first display panel including a common electrode disposed thereon, and a second display panel including; thin film transistors (“TFTs”) each including a gate electrode, a source electrode, and a drain electrode, a first passivation layer disposed on the source and drain electrodes, a second passivation layer disposed on the first passivation layer and including at least one sensing protrusion, pixel electrodes disposed on the second passivation layer and connected with the drain electrode, and at least one conductive member disposed on the sensing protrusion.

This application claims priority to Korean Patent Application No.10-2006-0015481, filed on Feb. 17, 2006, and all the benefits accruingtherefrom under 35 U.S.C. §119, the contents of which in its entiretyare herein incorporated by reference.

BACKGROUND OF THE INVENTION

(a) Field of the Invention

The present invention relates to a thin film transistor array panel anda display device.

(b) Description of the Related Art

Liquid crystal displays (“LCDs”), which are one type of flat paneldisplay devices, include two panels, one with pixel electrodes formedthereon and one with a common electrode formed thereon, and a liquidcrystal layer with dielectric anisotropy interposed between the twopanels. The pixel electrodes are arranged substantially in a matrix andare connected with switching elements such as thin film transistors(“TFTs”) to receive an image data voltage sequentially row by row. Thearea formed by each pixel electrode is referred to as a pixel, and anLCD may include a plurality of pixels. The common electrode is formed onthe entire surface of one of two panels and receives a common voltage. Apixel electrode, the corresponding portion of the common electrode, andcorresponding portion of the liquid crystal layer interposedtherebetween form a liquid crystal capacitor in terms of circuitry, andthe liquid crystal capacitor is a basic element of a pixel together withthe switching element connected thereto.

In the LCD, a voltage is applied to the two electrodes to generate anelectric field in the liquid crystal layer, and transmittance of lightwhich passes through the liquid crystal layer is controlled by varyingthe strength of the electric field to thus obtain a desired degree oflight transmittance. The degree of light transmittance may be nearlysimultaneously controlled in the plurality of pixels to generate animage.

Touch screen panels are input devices for enabling a user to interactwith a machine such as a computer by writing or drawing characters orfigures using a finger or a pen on a screen in a contact manner. Theinteraction may also be by using a finger or pen to press an on-screenbutton or icon to instruct the computer to perform an action. LCDsincluding the touch screen panels can recognize whether the finger ofthe user or the touch pen contacts on the screen and can also obtaincontact position information of the contact.

However, the LCD including the touch screen panel has problems in thatthe installation of the touch screen panel increases a unit cost, anadditional process of attaching the touch screen panel on a liquidcrystal panel assembly reduces production yield, luminance of the LCDdeteriorates, and a thickness of the product increases.

BRIEF SUMMARY OF THE INVENTION

Therefore, the present invention has been made in an effort to provide adisplay device having a sensing unit having advantages of accuratelysensing contact and a contact position.

The present invention has also been made in an effort to improvedurability of a sensing unit.

An exemplary embodiment of a thin film transistor (TFT) array panelincludes: a plurality of thin film transistors disposed on a substrateeach thin film transistor including a gate electrode, a sourceelectrode, and a drain electrode, a first passivation layer disposed onthe source and drain electrodes, and including a first contact holeexposing at least a portion of the drain electrode, a second passivationlayer disposed on the first passivation layer, and including at leastone sensing protrusion and a second contact hole, pixel electrodesdisposed on the second passivation layer connected with a drainelectrode through the first and second contact holes, and at least oneconductive member disposed on the sensing protrusion.

Another exemplary embodiment of a TFT array panel includes; a pluralityof TFTs disposed on a substrate and each including a gate electrode, asource electrode, and a drain electrode, a first passivation layerdisposed on the source and drain electrodes, and having a first contacthole exposing at least a portion of the drain electrode, pixelelectrodes disposed on the first passivation layer and connected with adrain electrode through the first contact hole, at least one conductivemember disposed on the first passivation layer, and at least one sensingprotrusion disposed on the conductive member.

The exemplary embodiment of a TFT array panel may further include asecond passivation layer disposed on the first passivation layer andincluding a second contact hole corresponding to the first contact hole.

In one exemplary embodiment the conductive member may includesubstantially the same material as the pixel electrode.

In one exemplary embodiment the conductive member may include indium tinoxide (“ITO”), indium zinc oxide (“IZO”), or a transparent conductiveorganic film.

In one exemplary embodiment the conductive member may be disposed on thesame layer on which the pixel electrode is disposed.

In one exemplary embodiment the second passivation layer may include anorganic insulator.

In one exemplary embodiment the TFT array panel may further includecolor filters disposed on the first passivation layer.

Another exemplary embodiment of a display device according to thepresent invention includes; a first display panel including a commonelectrode disposed thereon, and a second display panel including; aplurality of TFTs each including a gate electrode, a source electrode,and a drain electrode, a first passivation layer disposed on the sourceand drain electrodes, a second passivation layer disposed on the firstpassivation layer and including at least one sensing protrusion, pixelelectrodes disposed on the second passivation layer and connected withthe drain electrode, and at least one conductive member disposed on thesensing protrusion.

Still another exemplary embodiment of a display device includes; a firstdisplay panel including a common electrode disposed thereon, and asecond display panel including; a plurality of TFTs each including agate electrode, a source electrode, and a drain electrode, a firstpassivation layer disposed on the source and drain electrodes, pixelelectrodes disposed on the first passivation layer and connected withthe drain electrode, at least one conductive member disposed on thefirst passivation layer, and at least one sensing protrusion disposed onthe conductive member.

In one exemplary embodiment the display device may further include asecond passivation layer disposed on the first passivation layer.

The conductive member may include the same material as the pixelelectrode, and may include a transparent conductive organic film.

The conductive member may be disposed on the same layer on which thepixel electrode is formed.

The second passivation layer may include an organic insulator.

The sensing protrusion may include a transparent conductive organicfilm.

The first display panel may further include spacers disposed on thecommon electrode.

A height of the sensing protrusion may be lower than a height of thespacers.

The second display panel may further include color filters disposed onthe first passivation layer.

An exemplary embodiment of a method of manufacturing a thin filmtransistor array panel includes; disposing a plurality of thin filmtransistors on a substrate, each thin film transistor including a gateelectrode, a source electrode, and a drain electrode, disposing a firstpassivation layer on the source and drain electrodes, wherein the firstpassivation layer includes a first contact hole exposing at least aportion of the drain electrode, disposing a second passivation layer onthe first passivation layer, wherein the second passivation layerincludes at least one sensing protrusion and a second contact hole,disposing pixel electrodes on the second passivation layer, wherein thepixel electrodes are connected with the drain electrode through thefirst and second contact holes; and disposing at least one conductivemember on the sensing protrusion.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other aspects, features, and advantages of the presentinvention will become more apparent from the following detaileddescription of the present invention when taken in conjunction with theaccompanying drawings.

FIG. 1 is a schematic block diagram of an exemplary embodiment of aliquid crystal display (“LCD”) according to the present invention.

FIG. 2 is an equivalent circuit diagram of an exemplary embodiment ofone pixel of an exemplary embodiment of an LCD according to the presentinvention.

FIG. 3 is a schematic block diagram of an exemplary embodiment of an LCDaccording to the present invention.

FIG. 4 is an equivalent circuit diagram of an exemplary embodiment ofone sensing unit according to the present invention.

FIG. 5 is a schematic diagram of an exemplary embodiment of an LCDaccording to the present invention.

FIG. 6 is a top plan layout view of an exemplary embodiment of a thinfilm transistor (“TFT”) array panel according to the present invention.

FIG. 7A is a cross-sectional view taken along line VIIA-VIIA of theexemplary embodiment of a TFT array panel in FIG. 6.

FIG. 7B is a cross-sectional view taken along line VIIB-VIIB of theexemplary embodiment of a TFT array panel in FIG. 6.

FIG. 8 is another exemplary embodiment of a cross-sectional view takenalong line VIIA-VIIA of the TFT array panel in FIG. 6.

DETAILED DESCRIPTION OF THE INVENTION

The invention now will be described more fully hereinafter withreference to the accompanying drawings, in which embodiments of theinvention are shown. This invention may, however, be embodied in manydifferent forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the scope of the invention to those skilled in the art. Likereference numerals refer to like elements throughout.

It will be understood that when an element is referred to as being “on”another element, it can be directly on the other element or interveningelements may be present therebetween. In contrast, when an element isreferred to as being “directly on” another element, there are nointervening elements present. As used herein, the term “and/or” includesany and all combinations of one or more of the associated listed items.

It will be understood that, although the terms first, second, third etc.may be used herein to describe various elements, components, regions,layers and/or sections, these elements, components, regions, layersand/or sections should not be limited by these terms. These terms areonly used to distinguish one element, component, region, layer orsection from another element, component, region, layer or section. Thus,a first element, component, region, layer or section discussed belowcould be termed a second element, component, region, layer or sectionwithout departing from the teachings of the present invention.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention. Asused herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising,” or “includes” and/or “including” when used in thisspecification, specify the presence of stated features, regions,integers, steps, operations, elements, and/or components, but do notpreclude the presence or addition of one or more other features,regions, integers, steps, operations, elements, components, and/orgroups thereof.

Furthermore, relative terms, such as “lower” or “bottom” and “upper” or“top,” may be used herein to describe one element's relationship toanother elements as illustrated in the Figures. It will be understoodthat relative terms are intended to encompass different orientations ofthe device in addition to the orientation depicted in the Figures. Forexample, if the device in one of the figures is turned over, elementsdescribed as being on the “lower” side of other elements would then beoriented on “upper” sides of the other elements. The exemplary term“lower”, can therefore, encompasses both an orientation of “lower” and“upper,” depending of the particular orientation of the figure.Similarly, if the device in one of the figures is turned over, elementsdescribed as “below” or “beneath” other elements would then be oriented“above” the other elements. The exemplary terms “below” or “beneath”can, therefore, encompass both an orientation of above and below. [Theabove paragraph may be replaced with the following] Spatially relativeterms, such as “beneath”, “below”, “lower”, “above”, “upper” and thelike, may be used herein for ease of description to describe one elementor feature's relationship to another element(s) or feature(s) asillustrated in the figures. It will be understood that the spatiallyrelative terms are intended to encompass different orientations of thedevice in use or operation in addition to the orientation depicted inthe figures. For example, if the device in the figures is turned over,elements described as “below” or “beneath” other elements or featureswould then be oriented “above” the other elements or features. Thus, theexemplary term “below” can encompass both an orientation of above andbelow. The device may be otherwise oriented (rotated 90 degrees or atother orientations) and the spatially relative descriptors used hereininterpreted accordingly.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this invention belongs. It will befurther understood that terms, such as those defined in commonly useddictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art and thepresent disclosure, and will not be interpreted in an idealized oroverly formal sense unless expressly so defined herein.

Exemplary embodiments of the present invention are described herein withreference to cross section illustrations that are schematicillustrations of idealized embodiments of the present invention. Assuch, variations from the shapes of the illustrations as a result, forexample, of manufacturing techniques and/or tolerances, are to beexpected. Thus, embodiments of the present invention should not beconstrued as limited to the particular shapes of regions illustratedherein but are to include deviations in shapes that result, for example,from manufacturing. For example, a region illustrated or described asflat may, typically, have rough and/or nonlinear features. Moreover,sharp angles that are illustrated may be rounded. Thus, the regionsillustrated in the figures are schematic in nature and their shapes arenot intended to illustrate the precise shape of a region and are notintended to limit the scope of the present invention.

Hereinafter, the present invention will be described in detail withreference to the accompanying drawings.

An exemplary embodiment of a liquid crystal display (“LCD”) according tothe present invention, will now be described in detail with reference tothe accompanying drawings.

FIG. 1 is a schematic block diagram of an exemplary embodiment of an LCDaccording to the present invention, and FIG. 2 is an equivalent circuitdiagram of an exemplary embodiment of one pixel of an exemplaryembodiment of an LCD according to the present invention.

FIG. 3 is a schematic block diagram of an exemplary embodiment of an LCDaccording to the present invention, FIG. 4 is an equivalent circuitdiagram of an exemplary embodiment of one sensing unit according to thepresent invention, and FIG. 5 is a schematic diagram of an exemplaryembodiment of an LCD according to the present invention.

Referring to FIGS. 1 and 3, the exemplary embodiment of an LCD accordingto the present invention includes a liquid crystal panel assembly 300,an image scanning driver 400, an image data driver 500, and a sensesignal processor 800 connected with the liquid crystal panel assembly300, a gray voltage generator 550 connected with the image data driver500, a contact determiner 700 connected with the sense signal processor800, and a signal controller 600 for controlling the abovementionedcomponents.

Referring to FIGS. 1 to 4, the liquid crystal panel assembly 300includes a plurality of display signal lines G₁-G_(n) and D₁-D_(m), aplurality of pixels PX connected with the display signal lines G₁-G_(n)and D₁-D_(m) and arranged substantially in a matrix shape, a pluralityof sense signal lines SY₁-SY_(N) and SX₁-SX_(M), and a plurality ofsensing units SU connected with the sense signal lines SY₁-SY_(N) andSX₁-SX_(M) and arranged substantially in a matrix shape. Referring toFIGS. 2 and 5, the liquid crystal panel assembly 300 includes a thinfilm transistor (“TFT”) array panel 100 and a common electrode panel 200which face each other, a liquid crystal layer 3 interposed therebetween,and spacers (not shown) which maintain a gap between the two panels 100and 200 and which may be deformed to some extent by compression.

The signal lines G₁-G_(n) and D₁-D_(m) include a plurality of imagescanning lines G₁-G_(n) for transferring image scanning signals and aplurality of image data lines D₁-D_(m) for transferring image datavoltages, and the sense signal lines SY₁-SY_(N) and SX₁-SX_(M) include aplurality of horizontal sense data lines SY₁-SY_(N) and a plurality ofvertical sense data lines SX₁-SX_(M) for transferring sense datasignals.

In one exemplary embodiment the image scanning lines G₁-G_(n) and thehorizontal sense data lines SY₁-SY_(N) extend substantially in a rowdirection and are substantially parallel to each other, and the imagedata lines D₁-D_(m) and the vertical sense data lines SX₁-SX_(M) extendsubstantially in a column direction and are substantially parallel toeach other.

Each pixel PX includes a switching element Q which is connected to, ani-th (i=1, 2, . . . , n) image scanning line G_(i) and a j-th (j=1, 2, .. . , m) image data line D_(j), a liquid crystal capacitor Clc, and astorage capacitor Cst connected thereto. In alternative exemplaryembodiments the storage capacitor Cst may be omitted.

In one exemplary embodiment the switching element Q is a three-terminalelement such as the TFT provided on the TFT array panel 100, andincludes a control terminal connected to the image scanning line G_(j),an input terminal connected to the data line D_(j), and an outputterminal connected to the liquid crystal capacitor Clc and the storagecapacitor Cst. In such an exemplary embodiment, the TFT includesamorphous silicon or polycrystalline silicon.

The liquid crystal capacitor Clc includes a pixel electrode 191 of theTFT array panel 100 and a common electrode 270 of the common electrodepanel 200 as two terminals thereof, and the liquid crystal layer 3between the two electrodes 191 and 270 serves as a dielectric materialfor the liquid crystal capacitor Clc. The pixel electrode 191 isconnected to the switching element Q, and the common electrode 270 isformed on substantially the entire surface of the common electrode panel200 and receives a common voltage Vcom. In an alternative exemplaryembodiment, the common electrode 270 may be provided on the TFT arraypanel 100, and at least one of the two electrodes 191 and 270 may beformed in a linear or bar shape.

The storage capacitor Cst serves as an auxiliary to the liquid crystalcapacitor Clc and is formed as a signal line (not shown) separatelyprovided on the TFT array panel 100. In one exemplary embodiment thestorage capacitor is formed overlapping the pixel electrode 191 with aninsulator interposed therebetween. The storage capacitor Cst is suppliedwith a predetermined voltage such as the common voltage Vcom or thelike. Also, in one exemplary embodiment the storage capacitor Cst may beformed in the region where the pixel electrode 191 overlaps theimmediately previous image scanning line.

In order to display separate colors, each pixel PX inherently displaysone of a set of primary colors (spatial division) or sequentiallydisplay the primary colors (temporal division), so that a desired colormay be recognized by a spatial or temporal sum of the primary colors. Anexemplary embodiment of a set of the primary colors may include of red,green, and blue. FIG. 2 shows an exemplary embodiment of the spatialdivision in which a color filter (not shown) for displaying one of theprimary colors may be formed above or below the pixel electrode 191 ofthe TFT array panel 100. In an alternative exemplary embodiment eachpixel PX may have a color filter at a region of the common electrodepanel 200 corresponding to the pixel electrode 191.

At least one polarizer (not shown) is attached on an outer surface ofthe liquid crystal panel assembly 300.

The sensing unit SU may have a structure as shown in FIG. 4. The sensingunit SU as shown in FIG. 4, is an exemplary embodiment of a pressuresensing unit which includes a switch SWT connected with at least one ofthe horizontal or vertical sense data lines SY₁-SY_(N) or SX₁-SX_(M)(referred to hereinafter as “a sense data line” and indicated as SL),respectively.

The switch SWT has the common electrode 270 of the common electrodepanel 200 and the sense data line SL of the TFT array panel 100 as twoterminals thereof, and at least one of the two terminals projectstowards the other, the two terminals may be physically and electricallyconnected according to a user forcing contact therebetween. Accordingly,the common voltage Vcom from the common electrode 270 is outputted as asense data signal to the sense data line SL.

The structure and operation of the pressure sensing unit will now bedescribed in detail.

By analyzing a sense data signal flowing through the horizontal sensedata lines SY₁-SY_(N), the Y coordinate of a contact point may bedetermined, and by analyzing a sense data signal flowing through thevertical sense data lines SX₁-SX_(M), the X coordinate of the contactpoint may be determined.

The pressure sensing unit SU is disposed between adjacent pixels PX. Inone exemplary embodiment the plurality of pressure sensing units SU maybe disposed so that a density of a pair of sensing units SU connectedwith the horizontal and vertical sense data lines SY₁-SY_(N) andSX₁-SX_(M) and disposed to be adjacent to their crossing points may beabout one-fourths of a dot density wherein one dot includes three pixelsPX for displaying the three primary colors such as red, green, and bluewhich are arranged to display a color. The one dot is a basic unit forindicating resolution of the LCD. In alternative exemplary embodimentsthe one dot may include four or more pixels PX and, in such an exemplaryembodiment, each pixel PX may display one of the three primary colorsand a white color.

In one exemplary embodiment, when the density of the pair of sensingunits SU is one-fourth of the dot density, horizontal and verticalresolution of the pair of sensing units SU is half of the horizontal andvertical resolution of the LCD. In such an exemplary embodiment, theremay be a pixel row or a pixel column which does not have the sensingunit SU.

When the density of the sensing units SU and the dot are set to thedegree described above, the LCD is suitable for applications requiringhigh precision such as character recognition. However, the presentinvention is not limited to high precision applications and theresolution of the sensing units SU may be higher or lower and still bewithin the scope of the present invention.

Referring to FIGS. 1 and 3, in one exemplary embodiment the gray voltagegenerator 550 generates two sets of gray voltages (or reference grayvoltages) related to transmittance of the pixels PX. One of the two setsof gray voltages has a positive value and the other has a negative valuewith respect to the common voltage Vcom. The gray voltages applied tothe pixel electrodes 191 change polarity about the common voltage Vcomin order to change the orientation of the twisting force applied to theliquid crystal molecules. When the liquid crystal molecules are twistedin only one direction they may deteriorate more rapidly than if thetwisting force is of a varying orientation. Therefore, the applicationof gray voltages which change polarity with respect to the commonvoltage Vcom increases the lifetime of the LC panel assembly 300.

The image scanning driver 400 is connected with the image scanning linesG₁-G_(n) of the liquid crystal panel assembly 300 and applies imagescanning signals including a combination of a gate-on voltage Von forturning on the switching element Q and a gate-off voltage Voff forturning off the switching element Q substantially sequentially to theimage scanning lines G₁-G_(n).

The image data driver 500 is connected with the image data linesD₁-D_(m) of the liquid crystal panel assembly 300, selects a grayvoltage from the gray voltage generator 550, and applies it as an imagedata voltage to the image data lines D₁-D_(m). In the exemplaryembodiment wherein the gray voltage generator 550 provides only apredetermined number of reference gray voltages, the image data driver500 divides the reference gray voltages and thereby generates grayvoltages for all gray voltage values and selects an image data voltagetherefrom.

The sense signal processor 800 is connected with the sense data linesSY₁-SY_(N) and SX₁-SX_(M) of the liquid crystal panel assembly 300,receives a sense data signal outputted through the sense data linesSY₁-SY_(N) and SX₁-SX_(M), and processes it to generate a digital sensesignal DSN.

The contact determiner 700 receives the digital sense signal DSN fromthe sense signal processor 800 and determines whether the pressuresensing unit SU has been contacted or not and if it has been contactedalso determines a contact position thereof. In one exemplary embodimentthe contact determiner 700 may be formed as a central processing unit(“CPU”).

The signal controller 600 controls operations of the image scanningdriver 400, the image data driver 500, the gray voltage generator 550,and the sense signal processor 800.

In one exemplary embodiment the drivers 400, 500, 550, 600, 700, and 800may be directly mounted in the form of at least one integrated chip(“IC”) on the liquid crystal panel assembly 300. In another exemplaryembodiment the drivers 400, 500, 550, 600, 700, and 800 may be mountedon a flexible printed circuit film (not shown) which may be attached inthe form of a tape carrier package (“TCP”) on the liquid crystal panelassembly 300, or may be mounted on a separate printed circuit board(“PCB”) (not shown).

In yet another exemplary embodiment the drivers 400, 500, 550, 600, 700,and 800 may be integrated together with the signal lines G₁-G_(n),D₁-D_(m), SY₁-SY_(N), and SX₁-SX_(M) and TFT Q, on the liquid crystalpanel assembly 300.

Referring to FIG. 5, the liquid crystal panel assembly 300 is dividedinto a display region P1, an edge region P2, and an exposed region P3.The pixels PX, the sensing units SU, and the signal lines G₁-G_(n),D₁-D_(m), SY₁-SY_(N), and SX₁-SX_(M) are substantially positioned on thedisplay region P1. The common electrode panel 200 includes a lightblocking member 220, and the light blocking member 220 covers most partsof the edge region P2 in order to block external light. Because thecommon electrode panel 200 is smaller than the TFT array panel 100, aportion of the TFT array panel 100 is exposed to form the exposed regionP3. A single chip 610 is mounted on the exposed region P3 and a flexibleprinted circuit (“FPC”) board 620 is attached on the exposed region P3.

In the present exemplary embodiment the single chip 610 includes thedrivers, namely, the image scanning driver 400, the image data driver500, the gray voltage generator 550, the signal controller 600, thecontact determiner 700, and the sense signal processor 800, for drivingof the LCD. By integrating the drivers 400, 500, 550, 600, 700, and 800in the single chip 610, their mounting area and power consumption can bereduced. In alternative exemplary embodiments at least one of thedrivers or at least one circuit element constituting them may bepositioned outside the single chip 610.

The signal lines G₁-G_(n) and D₁-D_(m) and the sense data linesSY₁-SY_(N) and SX₁-SX_(M) extend to the exposed region P3 to connectwith the corresponding drivers 400, 500, and 800.

The FPC board 620 receives signals from an external device and transfersthem to the single chip 610 or the liquid crystal panel assembly 300,and in order to facilitate a connection with the external device, endsof the FPC board 620 are formed as a connector (not shown).

The displaying and sensing operations of the LCD will be described indetail as follows.

The signal controller 600 receives input image signals R, G, and B andinput control signals for controlling display of the input image signalsR, G, and B from an external device (not shown). The input image signalsR, G, and B include luminance information for each pixel PX, whereinluminance includes a predetermined number of gray levels, e.g., 1024(=2¹⁰), 256 (=2⁸), or 64 (=2⁶) gray levels. In one exemplary embodimentthe input control signals include a vertical synchronization signalVsync, a horizontal synchronization signal Hsync, a main clock signalMCLK, a data enable signal DE, and various other similar signals.

The signal controller 600 processes the input image signals R, G, and Baccording to operating conditions of the liquid crystal panel assembly300 based on the input image signals R, G, and B and the input controlsignal, then the signal controller 600 generates an image scanningcontrol signal CONT1 and an image data control signals CONT2, andvarious other image scanning control signals, and transmits the imagescanning control signal CONT1 to the image scanning driver 400 andtransmits the image data control signal CONT2 and the processed imagesignals DAT to the image data driver 500.

The image scanning control signal CONT1 includes a scanning start signalSTV for instructing starting of scanning and at least one clock signalfor controlling an output of the gate-on voltage Von. In one exemplaryembodiment the image scan control signal CONT1 may additionally includean output enable signal OE for limiting duration of the gate-on voltageVon.

The image data control signal CONT2 includes a horizontalsynchronization start signal STH for informing of starting oftransmission of the image signals DAT with respect to one row of pixelsPX, a load signal LOAD for indicating application of an image datavoltages to the image data lines D₁-D_(m), and a data clock signal HCLK.In one exemplary embodiment the image data control signal CONT2 mayadditionally include an inversion signal RVS for inverting polarity of avoltage of the image data voltages with respect to the common voltageVcom (which is called “polarity of image data voltage”) as describedabove.

The image data driver 500 receives the digital image signals DAT withrespect to one row of pixels PX according to the image data controlsignals CONT2 received from the signal controller 600, selects a grayvoltage corresponding to each digital image signal DAT to thus convertthe digital image signal DAT into an analog data voltage, and applies itto the corresponding image data lines D₁-D_(m).

The image scanning driver 400 applies the gate-on voltage Von to theimage scanning lines G₁-G_(n) according to the image scanning controlsignals CONT1 from the signal controller 600 to turn on the switchingelements Q connected with the image scanning lines G₁-G_(n). Then, theimage data voltages, which have been applied to the image data linesD₁-D_(m), are applied to the corresponding pixels PX through theturned-on switching elements Q.

A voltage is charged in the pixel PX according to a difference betweenthe voltage of the image data voltage applied to the pixels PX and thecommon voltage Vcom. This charged voltage is a pixel voltage of theliquid crystal capacitor Clc. Arrangement of liquid crystal molecules iscontrolled according to the size of the pixel voltage, and polarizationof light which is transmitted through the liquid crystal layer 3 ischanged accordingly. The change in the polarization appears as a changein transmittance of light due to the polarizer (not shown) attached onthe liquid crystal panel assembly 300. A plurality of pixels, eachcapable of independently controlling the arrangement of liquid crystalstherein and thereby also controlling the transmittance of lighttherethrough, may thereby display a desired image.

This process is repeatedly performed by a unit of one horizontal period(namely “1H” which is equivalent to one period of the horizontalsynchronization signal Hsync and the data enable signal DE), whereby thegate-on voltage Von is sequentially applied to all the image scanninglines G₁-G_(n) and the image data voltages are applied to all the pixelsPX to thus display an image of one frame.

When one frame is finished, a next frame is started and in one exemplaryembodiment a state of the inversion signal RVS applied to the image datadriver 500 is controlled (“frame inversion”) so that the polarity of thedata voltage applied to each pixel PX may be opposite to the polarity inthe previous frame. In such an exemplary embodiment using an inversionsignal RVS, the polarity of an image data voltage flowing through oneimage data line may be changed even within one frame according to theinversion signal RVS (e.g., row inversion or dot inversion), or thepolarity of image data voltages applied to one pixel row may bedifferent (e.g., column inversion or dot inversion).

The sense signal processor 800 converts sense data signals flowingthrough the sense data lines SY₁-SY_(N) and SX₁-SX_(M) to generatedigital sense signals DSN corresponding to X-axis and Y-axis contactpositions of the pressure sensing units SU connected with the sense datalines SY₁-SY_(N) and SX₁-SX_(M), and transfers the digital sense signalsDSN to the contact determiner 700.

Upon receiving the digital sense signals DSN, the contact determiner 700determines whether or not the pressure sensing units SU have beencontacted and if so a contact position thereof. As mentioned above, theexistence, and position, of a contact may be used to control anoperation corresponding to a command or menu selected by a user.

One exemplary embodiment of the LCD having the pressure sensing unitaccording to the present invention will now be described in detail withreference to FIGS. 6-7B.

FIG. 6 is a top plan layout view of an exemplary embodiment of a TFTarray panel according to the present invention, FIG. 7A is across-sectional view taken along line VIIA-VIIA of the exemplaryembodiment of a TFT array panel in FIG. 6, and FIG. 7B is across-sectional view taken along line VIIB-VIIB of the exemplaryembodiment of a TFT array panel in FIG. 6.

As mentioned above, the exemplary embodiment of an LCD according to thepresent invention includes the TFT array panel 100, the common electrodepanel 200 which faces the TFT array panel 100, and the liquid crystallayer 3 interposed between the TFT array panel 100 and the commonelectrode panel 200.

The TFT array panel 100, which is the lower panel, is described below.

A plurality of image scanning lines 121, a plurality of horizontal sensedata lines 126, and a plurality of storage electrode lines 131 areformed on an insulating substrate 110. Exemplary embodiments of theinsulating substrate 110 are made of transparent glass or plastic.

The image scanning lines 121 transfer image scanning signals and extendsubstantially in a horizontal direction. Image scanning lines 121include a plurality of gate electrodes 124 which protrude verticallyupward towards a storage electrode line 131 and a large end portion 129which connects with a different layer or an external driving circuit. Inone exemplary embodiment the gate electrode 124 has a chamfered portion.Image scanning driving circuits (not shown) for generating imagescanning signals may be mounted on a flexible printed circuit film (notshown) attached on the substrate 110, directly mounted on the substrate110, or integrated with the substrate 110. When the image scanningdriving circuits is integrated with the substrate 110, the imagescanning lines 121 may be elongated to be directly connected thereto andtherefore the large end portion 129 may be omitted.

The horizontal sense data lines 126 transfer sense data signals andextend substantially in a horizontal direction. Each horizontal sensedata line 126 extends a certain length in a vertical direction andincludes an extended portion 126 a including a portion with a largewidth. The extended portion 126 a branches from the horizontal datalines 126. Each horizontal sense data line 126 may include an endportion with a larger area (not shown) for a connection with a differentlayer or an external driving circuit.

Each storage electrode line 131 is separated from the image scanninglines 121, and extends substantially in the horizontal direction, andincludes a plurality of expanded portions 137 which are protrudedvertically downward toward the image scanning line 121. A certainvoltage is applied to the storage electrode lines 131, one exemplaryembodiment of which is the common voltage applied to the commonelectrode 270 of the common electrode panel 200 of the LCD.

In one exemplary embodiment the image scanning lines 121, the horizontalsense data lines 126, and the storage electrode lines 131 may be made ofan aluminum containing metal such as aluminum (A) or an aluminum alloy,a silver containing metal such as silver (Ag) or a silver alloy, acopper containing metal such as copper (Cu) or a copper alloy, amolybdenum containing metal such as molybdenum (Mo) or a molybdenumalloy, chromium (Cr), tantalum (Ta), titanium (Ti), or various othermaterials with similar characteristics. In an alternative exemplaryembodiment the image scanning lines 121, the horizontal sense data lines126, and the storage electrode lines 131 may have a multi-layeredstructure including two conductive layers (not shown) each havingdifferent physical properties. In such an alternative exemplaryembodiment one of the conductive layers may be made of a metal with lowresistivity, exemplary embodiments of which include the aluminumcontaining metal, the silver containing metal, the copper containingmetal, or the other materials listed above, in order to reduce a signaldelay or a voltage drop. The other conductive layer in such analternative exemplary embodiment may be made of a material which hasgood physical, chemical, and electrical contact characteristics withother materials, particularly with indium tin oxide (“ITO”) and indiumzinc oxide (“IZO”), exemplary embodiments of which include anmolybdenum-based metal, chromium, tantalum, titanium, or other materialswith similar characteristics. Exemplary embodiments of such acombination may include a combination of a lower chromium layer and anupper aluminum (alloy) layer, and a combination of a lower aluminum(alloy) layer and an upper molybdenum (alloy) layer. In addition, theimage scanning lines 121, the horizontal sense data lines 126, and thestorage electrode lines 131 may be made of various other metals orconductors.

According to one exemplary embodiment the sides of the image scanninglines 121, the horizontal sense data lines 126, and the storageelectrode lines 131 are sloped relative to the surface of the insulatingsubstrate 110. in one exemplary embodiment the slope angle is about 30°to about 80°.

A gate insulating layer 140, exemplary embodiments of which may be madeof silicon nitride (“SiNx”) or silicon oxide (“SiOx”), or othermaterials with similar characteristics, is formed on the image scanninglines 121, the horizontal sense data lines 126, and the storageelectrode lines 131.

A plurality of semiconductor islands 154 made of hydrogenated amorphoussilicon (“a-Si”) or polycrystalline silicon, or other substances withsimilar characteristics, are formed on the gate insulating layer 140. Inthe present exemplary embodiment the semiconductor islands 154 arepositioned at an upper side of the gate electrodes 124.

A plurality of ohmic contact islands 163 and 165 are formed on thesemiconductor islands 154. In one exemplary embodiment the ohmic contactislands 163 and 165 may be made of a material such as n+ hydrogenatedamorphous silicon in which high density of an n-type impurity such asphosphor is doped, or in an alternative exemplary embodiment the ohmiccontact islands 163 and 165 may be made of silicide. The ohmic contactislands 163 and 165 are disposed as a pair on the semiconductor islands154.

In one exemplary embodiment the sides of the semiconductor islands 154and the ohmic contact islands 163 and 165 are also sloped to thesubstrate 110, and the slope angle is about 30° to about 80°.

A plurality of image data lines 171, a plurality of drain electrodes175, and a plurality of vertical sense data lines 174 are formed on theohmic contact islands 163 and 165 and the gate insulating layer 140.

The image data lines 171 transfer image data signals and extendsubstantially in a vertical direction and cross the image scanning lines121, but are not electrically connected thereto. Each image data line171 includes a plurality of source electrodes 173 extending toward thegate electrodes 124 and a large end portion 179 for a connection with adifferent layer or an external driving circuit. Again, in the exemplaryembodiment wherein connections are made directly with the drivingapparatus the large end section 179 may be omitted. Image data drivingcircuits (not shown) may be mounted on the flexible printed circuit film(not shown) attached on the substrate 110, directly mounted on thesubstrate 110, or integrated with the substrate 110. When the image datadriving circuits are integrated with the substrate 110, the image datalines 171 may be elongated to be directly connected thereto as mentionedabove.

Each drain electrode 175 is separated from the image data line 171 andfaces the source electrode 173 centering on the gate electrode 124. Eachdrain electrode 175 includes one large end portion including an expandedportion 177 and a separate narrow end portion opposing the expandedportion. The expanded portion 177 overlaps with the storage electrodeline 131 and the narrow end portion is partially surrounded by thesource electrode 173.

One gate electrode 124, one source electrode 173, and one drainelectrode 175 together form a TFT with the semiconductor island 154, anda channel of the TFT is formed at the semiconductor island 154 betweenthe source electrode 173 and the drain electrode 175.

The vertical sense data lines 174 transfer sense data signals and extendsubstantially in the vertical direction. In the present exemplaryembodiment the vertical sense data lines 174 extend separately from theadjacent image data lines 171. Each vertical sense data line 174includes an expanded portion 174 a with a large width and may include anend portion (not shown) with a large area for a connection with adifferent layer or an external driving circuit.

In one exemplary embodiment the image data lines 171, the drainelectrodes 175, and the vertical sense data lines 174 are made of arefractory metal such as molybdenum, chromium, tantalum, titanium, orother material with similar characteristics, or their alloys, and in oneexemplary embodiment may have a multi-layered structure including arefractory metal layer as described above (not shown) and alow-resistance conductive layer as described above (not shown).Exemplary embodiments of the multi-layered structure may include adouble-layered structure including a lower chromium or molybdenum(alloy) layer and an upper aluminum (alloy) layer, and a triple-layeredstructure including a lower molybdenum (alloy) layer, an intermediatealuminum (alloy) layer, and an upper molybdenum (alloy) layer. Also, theimage data lines 171, the drain electrodes 175, and the vertical sensedata lines 174 may be made of various other metals or conductors.

In one exemplary embodiment the sides of the image data line 171, thedrain electrode 175, and the vertical sense data line 174 are slopedwith respect to the surface of the substrate 110 at a slope angle ofabout 30° to about 80°.

The ohmic contact islands 163 and 165 are disposed between the lowersemiconductor island 154 and the upper image data line 171 and the drainelectrode 175, in order to lower contact resistance therebetween. Someportions of the semiconductor island 154 including a portion between thesource electrode 173 and the drain electrode 175 are exposed withoutbeing covered by the image data line 171 and the drain electrode 175.

A lower passivation layer 180 p is formed on the image data line 171 andthe drain electrode 175, and on the exposed portion of the semiconductorisland 154. In one exemplary embodiment the lower passivation layer 180p is made of an inorganic insulator such as silicon nitride or siliconoxide.

Color filters 230 in a stripe shape are formed on the lower passivationlayer 180 p. In one exemplary embodiment each color filter 230 includesone of the primary colors such as red, green, and blue. The colorfilters 230 are positioned between two adjacent image data lines 171.The neighboring color filters 230 overlap at an upper side of the imagedata lines 171 and the vertical sense data lines 174 to substantiallyprevent light leakage between pixel electrodes 191. The color filters230 are not disposed in the peripheral area of the end portions 129 ofthe image scanning lines 121 and the end portions 179 of the image datalines 171. Additionally the color filters 230 include a plurality ofopenings positioned on the drain electrode 175. The openings expose aportion of each drain electrode 175 and the lower passivation layer 180p.

An edge portion of each color filter 230 may have a thickness smallerthan that of other portions in order to obtain better step coveragecharacteristics of an upper layer and seek planarization of the TFTarray panel 100 to thus prevent misalignment of liquid crystals. Thecolor filters completely cover the image data lines 171 and the verticalsense data lines 174. Edges of the neighboring color filters 230 may beprecisely conformed to each other so that the entire display region iscovered by overlapping color filters 230.

An upper passivation layer 180 q, exemplary embodiments of which aremade of an organic insulating material, is formed on the color filters230 and includes a plurality of sensing protrusions 184 a and 184 b. Inone exemplary embodiment the organic insulating material has adielectric constant of 4.0 or less, and may have photosensitivity andmay form a planarized surface. In an alternative exemplary embodimentinstead of the upper and lower passivation layers 180 p and 180 q, thepassivation layer may have a single-layered structure made of aninorganic insulating material or the organic insulating material.

The expanded portion 174 a is formed at a position corresponding to theplurality of sensing protrusions 184 a and 184 b to thus allow thebottoms of the plurality of sensing protrusions 184 a and 184 b to bemaintained at the same level. In one exemplary embodiment contact gapsbetween the common electrode 270 and the vertical sense data lines 174and contact gaps between the common electrode 270 and the horizontalsense data lines 126 are substantially similar.

A plurality of contact holes 187, 182, and 183 a are formed at the upperand lower passivation layers 180 q and 180 p, exposing the expandedportions 177 of the drain electrodes 175, the end portions 179 of theimage data lines 171, and the expanded portions 174 a of the verticalsense data lines 126, and a plurality of contact holes 181 and 183 b arealso formed at the upper and lower passivation layers 180 q and 180 p,exposing the end portions 129 of the image scanning lines 121 and theexpanded portions 126 a of the horizontal sense data lines 126 togetherwith the gate insulating layer 140. The contact holes 181, 182, 183 a,183 b, and 187 have sloped sides, respectively. Accordingly, the lowerpassivation layer 180 p and the upper passivation layer 180 q have acorresponding geometry at the contact holes 181, 182, and 187. Also, aportion of an upper surface of the color filter 230 may be exposed tomake the contact hole 187 have a stepped profile.

A plurality of pixel electrodes 191, a plurality of conductive members194 a and 194 b, and a plurality of contact assistants 81 and 82 areformed on the passivation layers 180 p and 180 q. In one exemplaryembodiment the pixel electrodes 191, the conductive members 194 a and194 b, and the contact assistants 81 and 82 may be made of a transparentconductive material such as ITO or IZO, or of a reflective metal such asaluminum, silver, chromium, or alloys thereof.

The pixel electrode 191 is physically and electrically connected withthe drain electrode 175 via the contact hole 187 and receives an imagedata voltage from the drain electrode 175. The pixel electrode 191, towhich the image data voltage has been applied, generates an electricfield together with the common electrode 270 of the common electrodepanel 200, wherein the common electrode 270 receives the common voltage.The electric field determines a direction of orientation of the liquidcrystal molecules (not shown) of the liquid crystal layer 3 between thetwo electrodes 191 and 270. Polarization of light which transmitsthrough the liquid crystal layer 3 differs depending on the thuslydetermined direction of the liquid crystal molecules. The pixelelectrode 191 and the common electrode 270 form the liquid crystalcapacitor Clc, described above with reference to FIGS. 1-3, to sustainthe applied voltage even after the TFT is turned off.

The pixel electrode 191 and the drain electrode 175 connected with thepixel electrode 191 overlap the storage electrode line 131. The pixelelectrode 191 and the drain electrode 175 electrically connected theretooverlap with the storage electrode line 131 to form the storagecapacitor Cst, as described above with reference to FIGS. 1-3, whichstrengthens the voltage storage capability of the liquid crystalcapacitor.

The pixel electrode 191 may overlap with the neighboring image scanningline 121 and the image data line 171 to increase the aperture ratio ofthe pixel PX.

The conductive member 194 a and 194 b are formed on the sensingprotrusions 184 a and 184 b, respectively.

The contact assistants 81 and 82 are connected with the end portions 129of the image scanning lines 121 and the end portions 179 of the imagedata line 171 through the contact holes 181 and 182, respectively. Thecontact assistants 81 and 82 enhance the adhesion between the endportions 129 and 170 and external devices, and protect the end portions129 and 179 from damage such as corrosion, scratching, or other defects.

A transparent conductive organic film, or other similar substance, maybe used the pixel electrode 191 and the conductive members 184 a and 184b, and in of the exemplary embodiment wherein the LCD is a reflectiveLCD, an opaque reflective metal may be used. In such an exemplaryembodiment, the contact assistants 81 and 82 may be made of a differentmaterial from the pixel electrodes 191, including IZO or ITO.

The structure of the common electrode panel 200 will be described below.

The common electrode 270 is formed on an insulating substrate 210,exemplary embodiments of which are made of transparent glass or plastic.In one exemplary embodiment the common electrode 270 is made of atransparent conductor such as ITO or IZO. The common voltage Vcom isapplied to the common electrode 270.

A plurality of spacers 320, exemplary embodiments of which are columnshaped and made of an organic material, are formed on the commonelectrode 270. In an alternative exemplary embodiment the spacers 320may be made on the pixel electrode 191 of the TFT array panel 100.

The columnar spacers 320 are formed between the pixels PX or within eachpixel PX, and are uniformly dispersed on the liquid crystal panelassembly 300. The columnar spacers 320 maintain a gap between the TFTarray panel 100 and the common electrode panel 200 and are higher thanthe sensing protrusions 184 a and 184 b of the TFT array panel 100.

Although not shown, one exemplary embodiment includes a light blockingmember, also called a black matrix, formed at a lower portion of thecommon electrode 270. The light blocking member has openings at portionscorresponding to pixels PX surrounded by the image scanning lines 121and the image data lines 171, and is made of an organic materialincluding a black pigment which blocks light which may leak betweenneighboring pixels PX. In such an exemplary embodiment, an overcoat madeof an insulating material, exemplary embodiments of which includeorganic material, may be formed on the insulating substrate 210 with thelight blocking member formed thereon.

An alignment layer (not shown) for aligning the liquid crystal layer 3is coated on each inner surface of the panels 100 and 200, and one ormore polarizers (not shown) are provided on each outer surface of thepanels 100 and 200.

In one exemplary embodiment the LCD may further include a sealant (notshown) binding the TFT array panel 100 and the common electrode panel200. The sealant is positioned on an edge portion of the commonelectrode panel 200.

The liquid crystal layer 3 is interposed between the TFT array panel 100and the common electrode panel 200, and because the two panels 100 and200 are supported by the columnar spacers 320, a certain gap issustained between the conductive members 194 a and 194 b which cover thesensing protrusions 184 a and 184 b and the common electrode 270. In oneexemplary embodiment the gap is about 0.001 μm or greater.

In an alternative exemplary embodiment the gap between the two panels100 and 200 may be supported by bead spacers (not shown) instead of, orin addition to, the columnar spacers 320.

The common electrode 270 and the conductive members 194 a and 194 bcovering the sensing protrusions 184 a and 184 b form a switch SWT ofthe pressure sensing unit. Thus, when the common electrode panel 200 iscompressed towards the TFT array panel 100 by a contact, such as thatcaused by a finger of a user, the common electrode 270 of the commonelectrode panel 200 is electrically and physically connected with theconductive members 194 a and 194 b covering the sensing protrusions 184a and 184 b, respectively, of the TFT array panel 100 at the point ofcontact. Accordingly, the common voltage Vcom is transferred to theconductive members 194 a and 194 b so as to conduct a sense data signalto the corresponding horizontal or vertical sense data lines 126 and 174through the corresponding contact holes 183 a and 183 b.

The process of making the contact between the common electrode 270 andthe sensing protrusions 184 a and 184 b becomes easier when the commonelectrode panel 200 is made to be thin. In one exemplary embodiment thethickness of the common electrode panel 200 is about 0.1 mm to about 1mm.

As described above, the vertical sense data lines 174 where the switchSWT of the pressure sensing unit is formed are formed between adjacentpixels PX at every one of a certain number of dot columns. Virtualvertical sense data lines (not shown), which are similar to the verticalsense data lines except that no switch is formed therein, are formedbetween dots where the vertical sense data lines 174 are not formed tomaintain a substantially constant gap between dots.

Also, as described above, the horizontal sense data lines 126 where theswitches SWT of the pressure sensing units are formed are formed atevery certain number of dot rows, and virtual horizontal sense datalines (not shown), which are similar to the horizontal sense data linesexcept that no switches are formed therein, are formed at pixel rowswhere the horizontal sense data lines 126 are not formed.

By forming such virtual vertical and horizontal sense data lines, adefect of vertical line or horizontal line pattern caused by adifference of capacitance can be reduced.

Another exemplary embodiment of the LCD having the pressure sensingunits according to the present invention will now be described indetail.

FIG. 8 is another exemplary embodiment of a cross-sectional view takenalong line VIIA-VIIAa of the TFT array panel in FIG. 6.

The layered structure of the LCD as shown in FIG. 8 is substantially thesame as that shown in FIG. 7.

In the exemplary embodiment of a TFT array panel 100′, a plurality ofhorizontal sense data lines 126 including a plurality of image scanninglines 121 and extended portions 126 b are formed on the substrate 110,on which a gate insulating layer 140, a plurality of semiconductorislands 154, and a plurality of ohmic contact islands 163 and 165 aresequentially formed. On the ohmic contact islands 163 and 165 and thegate insulating layer 140, there are formed a plurality of image datalines 171 including a plurality of source electrodes 173 and a pluralityof vertical sense data lines 174 including a plurality of drainelectrodes 175 and a plurality of expanded portions 174 b, on which alower passivation layer 180 p is formed.

Color filters 230 are formed on the lower passivation layer 180 p, andan upper passivation layer 180 q is formed on the color filters 230.

A plurality of contact holes 181, 182, 183 a, 183 b, and 187 are formedon the passivation layers 180 p and 180 q or the gate insulating layer140, and a plurality of pixel electrodes 191 and a plurality of contactassistants 81 and 82 are formed on the passivation layer 180 q.

Unlike the TFT array panel 100 of the LCD as shown in FIG. 7 in whichthe sensing protrusions 184 a and 184 b are formed on the upperpassivation layer 180 q, the TFT array panel 100′ of the LCD as shown inFIG. 8 is formed such that a plurality of conductive members 194 a′ and194 b′ are formed on the upper passivation layer 180 q along with thepixel electrodes 191, and sensing protrusions 195 a and 195 b are formedon the conductive members 194 a′ and 194 b′.

According to this alternative exemplary embodiment the sensingprotrusions 195 a and 195 b may be made of a transparent conductivematerial, exemplary embodiments of which include a transparentconductive organic film such as polypyrrole, polyphenylene, andpolyanilline. However, alternative exemplary embodiments includeconfigurations wherein the sensing protrusions 195 a and 195 b may bemade of an opaque conductive material. In such an exemplary embodiment,the sensing protrusions 194 a and 195 b are formed between pixels PX soas not to affect the aperture ratio of the pixels PX.

In the TFT array panel 100′ as shown in FIG. 8, the upper passivationlayer 180 q is formed on the color filters 230 to protect the colorfilters 230, and alternative exemplary embodiments includeconfigurations wherein the upper passivation layer 180 q may be omitted.

A common electrode panel 200 as shown in FIG. 8 has substantially thesame layered structure as that of shown in FIG. 7. Namely, a commonelectrode 270 is formed on the insulating substrate 210, and columnarspaces 320 are formed on the common electrode 270.

Because the two panels 100 and 200 are supported by the plurality ofcolumnar spacers 320, a certain gap is sustained between the sensingprotrusions 195 a and 195 b and the common electrode 270. Again, in oneexemplary embodiment the gap is about 0.001 μm.

In one exemplary embodiment of the present invention, the method ofmanufacturing the above described exemplary embodiment of a TFT arraypanel 100′ uses five sheets of masks. However the present invention mayalso be applied to structures which use three or four sheets of masks inthe manufacturing method thereof.

Pressure sensing units are used as sensing units in the above-describedexemplary embodiments of the present invention, however the presentinvention is not limited thereto and sensing units which use variablecapacitors with a capacitance which changes depending on pressureapplied from an external source or optical sensors whose output signalschange according to intensity of light received thereby mayalternatively also be used. In yet another alternative exemplaryembodiment the exemplary embodiment of a display device of the presentinvention can improve the accuracy of contact determination by includingtwo or more types of sensing units.

The present invention has been described with reference to exemplaryembodiments wherein the display device is an LCD, however the presentinvention may also be applied in the same manner for a plasma displaydevice or an organic light emitting display, or various other types ofdisplay devices.

In the above-described exemplary embodiment of the present invention,the sensing units for sensing contact is installed within the displaydevice and therefore the thickness and volume of the display device canbe reduced, the fabrication process is simplified, and the fabricationcost can also be reduced.

In addition, because the sensing protrusions are not formed on thecommon electrode panel, which is the upper panel which would becompressed by an external pressure, but on the TFT array panel,durability of the sensing protrusions can be enhanced. The sensingprotrusions are protected from the flexing forces applied to the commonelectrode panel and therefore may have increased lifetimes.

Moreover, because the color filters are formed on the TFT array panelwith the TFTs formed thereon, misalignment between color filters andpixel electrodes which are formed on different panel can be reduced.

While this invention has been described in connection with what ispresently considered to be practical exemplary embodiments, it is to beunderstood that the invention is not limited to the disclosed exemplaryembodiments, but, on the contrary, is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the appended claims.

1. A thin film transistor array panel comprising: a plurality of thinfilm transistors disposed on a substrate each thin film transistorincluding a gate electrode, a source electrode, and a drain electrode; afirst passivation layer disposed on the source and drain electrodes, andincluding a first contact hole exposing at least a portion of the drainelectrode; a second passivation layer disposed on the first passivationlayer, and including at least one sensing protrusion and a secondcontact hole; pixel electrodes disposed on the second passivation layerconnected with the drain electrode through the first and second contactholes; and at least one conductive member disposed on the sensingprotrusion, wherein an upper surface of the sensing protrusion is higherthan a surface of the second passivation layer.
 2. The thin filmtransistor array panel of claim 1, wherein the conductive membercomprises substantially the same material as the pixel electrodes. 3.The thin film transistor array panel of claim 2, wherein the conductivemember comprises indium tin oxide or indium zinc oxide.
 4. The thin filmtransistor array panel of claim 2, wherein the conductive membercomprises a transparent conductive organic film.
 5. The thin filmtransistor array panel of claim 2, wherein the conductive member isdisposed on the same layer on which the pixel electrode is disposed. 6.The thin film transistor array panel of claim 2, wherein the secondpassivation layer comprises an organic insulator.
 7. The thin filmtransistor array panel of claim 1, further comprising color filtersdisposed on the first passivation layer.
 8. A thin film transistor arraypanel comprising: a plurality of thin film transistors disposed on asubstrate and each including a gate electrode, a source electrode, and adrain electrode; a first passivation layer disposed on the source anddrain electrodes, and having a first contact hole exposing at least aportion of the drain electrode; a second passivation layer disposed onthe first passivation layer; pixel electrodes disposed on the firstpassivation layer and connected with the drain electrode through thefirst contact hole; at least one conductive member disposed on the firstpassivation layer; and at least one sensing protrusion disposed on theconductive member, wherein an upper surface of the sensing protrusion ishigher than a surface of the second passivation layer.
 9. The thin filmtransistor array panel of claim 8, wherein the second passivation layerhas a second contact hole corresponding to the first contact hole. 10.The thin film transistor array panel of claim 8, wherein the conductivemember comprises substantially the same material as the pixel electrode.11. The thin film transistor array panel of claim 10, wherein theconductive member is made of indium tin oxide or indium zinc oxide. 12.The thin film transistor array panel of claim 8, wherein the conductivemember comprises a transparent conductive organic film.
 13. The thinfilm transistor array panel of claim 8, wherein the conductive member isdisposed on the same layer on which the pixel electrode is disposed. 14.The thin film transistor array panel of claim 8, wherein the sensingprotrusion comprises a transparent conductive organic film.
 15. The thinfilm transistor array panel of claim 8, further comprising color filtersdisposed on the first passivation layer.
 16. A display devicecomprising: a first display panel including a common electrode disposedthereon; and a second display panel comprising: a plurality of thin filmtransistors each including a gate electrode, a source electrode, and adrain electrode; a first passivation layer disposed on the source anddrain electrodes; a second passivation layer disposed on the firstpassivation layer and including at least one sensing protrusion; pixelelectrodes disposed on the second passivation layer and connected withthe drain electrode; and at least one conductive member disposed on thesensing protrusion, wherein an upper surface of the sensing protrusionis higher than a surface of the second passivation layer.
 17. Thedisplay device of claim 16, wherein the conductive member comprisessubstantially the same material as the pixel electrode.
 18. The displaydevice of claim 17, wherein the conductive member comprises atransparent conductive organic film.
 19. The display device of claim 16,wherein the conductive member is disposed on the same layer on which thepixel electrode is disposed.
 20. The display device of claim 16, whereinthe second passivation layer comprises an organic insulator.
 21. Thedisplay device of claim 16, wherein the first display panel furthercomprises spacers disposed on the common electrode.
 22. The displaydevice of claim 21, wherein a height of the sensing protrusion is lowerthan a height of the spacers.
 23. The display device of claim 16,wherein the second display panel further comprises color filtersdisposed on the first passivation layer.
 24. A display devicecomprising: a first display panel including a common electrode disposedthereon; and a second display panel comprising: a plurality of thin filmtransistors each including a gate electrode, a source electrode, and adrain electrode; a first passivation layer disposed on the source anddrain electrodes; a second passivation layer disposed on the firstpassivation layer; pixel electrodes disposed on the first passivationlayer and connected with the drain electrode; at least one conductivemember disposed on the first passivation layer; and at least one sensingprotrusion disposed on the conductive member, wherein an upper surfaceof the sensing protrusion is higher than a surface of the secondpassivation layer.
 25. The display device of claim 24, furthercomprising a second passivation layer disposed on the first passivationlayer.
 26. The display device of claim 24, wherein the conductive membercomprises the same material as the pixel electrode.
 27. The displaydevice of claim 24, wherein the conductive member is disposed on thesame layer on which the pixel electrode is disposed.
 28. The displaydevice of claim 24, wherein the sensing protrusion comprises atransparent conductive organic film.
 29. The display device of claim 24,wherein the first display panel further comprises spacers disposed onthe common electrode.
 30. The display device of claim 29, wherein aheight of the sensing protrusion is lower than a height of the spacers.31. The display device of claim 24, wherein the second display panelfurther comprises color filters disposed on the first passivation layer.32. A method of manufacturing a thin film transistor array panel, themethod comprising: disposing a plurality of thin film transistors on asubstrate, each thin film transistor including a gate electrode, asource electrode, and a drain electrode; disposing a first passivationlayer on the source and drain electrodes, wherein the first passivationlayer includes a first contact hole exposing at least a portion of thedrain electrode; disposing a second passivation layer on the firstpassivation layer, wherein the second passivation layer includes atleast one sensing protrusion and a second contact hole; disposing pixelelectrodes on the second passivation layer, wherein the pixel electrodesare connected with the drain electrode through the first and secondcontact holes; and disposing at least one conductive member on thesensing protrusion, wherein an upper surface of the sensing protrusionis higher than a surface of the second passivation layer.